Gas turbine engines may comprise multiple gas flows at different temperatures and pressures. For example, the engine may have a primary or core air flow and a separate cooling air flow. Gas in the primary or core airflow in a turbine section, for example may be hot compared to the cooling air flowing in internal cavities of the turbine parts. In some locations, seals may be used to prevent or limit the bleed gas from one area of the engine to another.
One location of the engine where sealing may be used is between a blade outer air seal and a vane in a turbine. In some instances, the blade outer air seal and vane may have a large relative axial motion between them. The large axial motion combined with a large pressure differential between the cooling air and primary airflow air may lead to gas leaking from one section of the engine to another.